My class post to their e-portfolio blogs and class blog using iPads, which give an ok but not great experience. We usually write in the notes app, paste over and add media. I am worried, still, about the transition to Gutenberg.
As an apple user lot of the friction, for me has been solved by micro.blog. I mostly posts photos on the go. It is harder to write IndieWeb replies, bookmarks etc. while mobile. Adding a footnote is easy on my laptop, but I wouldn’t want to try on my phone.
There is certainly room of an app or WordPress plugin that would give a very cutback experience. One of the great things about micro.blog is that posting images does not fill up your editor screen and make text harder to add in the way the WordPress editor does.